Air filter mediums are often installed in the ducting of air conditioning systems to remove dust and airborne particulates from the airflow. Over time these air filter mediums can become dirty and, as the filter mediums become dirty, the airflow through the ducting is impeded. If the airflow through the ducting is impeded to any significant extent, the consequence is that less cooled air can be delivered to the environment that is being cooled. In order to avoid this and maintain an efficient air conditioning system, dirty filter mediums in the ducting should be periodically replaced with clean filter mediums.
In some air conditioning systems, it is difficult to determine whether a filter medium is dirty and needs to be cleaned or replaced because the filter medium is positioned internally within the ducting and cannot be observed. Further, when replacing dirty filter mediums in the ducting with clean filter mediums, the air conditioning system may need to be stopped. While the air conditioning system is stopped, the environment which was being cooled by the air conditioning system will heat up. Once the air conditioning system is restarted, energy is wasted in returning the environment to the desired temperature. To maximize the efficiency of the air conditioning system, then, it is desirable to determine the cleanliness of the filter medium in the ducting and then replace a dirty filter medium without stopping the air conditioning system.
With the above in mind, it is an object of the present invention to provide an automatic filter cartridge for an air conditioning system to determine when a dirty filter medium is impeding the airflow through the ducting by monitoring certain characteristics of the airflow. It is another object of the present invention to provide an automatic filter cartridge for an air conditioning system which can replace the filter medium in the ducting without stopping the air conditioning system. Yet another object of the present invention is to provide an filter cartridge for an air conditioning system in which the replacement of dirty filter medium with clean filter medium can be easily accomplished. Another object of the invention is to provide a filter cartridge for a ducting of an air conditioning system, together with its method of operation, which is relatively easy to manufacture, simple to use, and comparatively cost effective.